The white 'local' pipe is for controls at the Scope side independent of SCOPESYNC automation. Examples of this might be VU meters / clip LEDs or if you wanted to use multiple SCOPESYNC instances in a patch and call up other UI windows from controls on the main SCOPESYNC UI. The means to do this is available via the CP<->Host pipe of the SS128A which is itself tapped into 8 of the 16 available ScopeLocal connections.

The yellow 128pipe was added with CLMs in mind. You could have a patch with a single SS128A and multiple CLMs. The Yellow pipe would at least in theory make it easier to connect the CLM contents to the SS128A. What you suggest however as a use might well work too